JP5927039B2 - Electronic endoscope apparatus and imaging module thereof - Google Patents

Description

  The present invention relates to an electronic endoscope apparatus and an imaging module thereof, and more particularly, to an electronic endoscope apparatus and an imaging module thereof that are provided with a countermeasure against flare.

  In an electronic endoscope apparatus that has a built-in imaging module at the distal end of an endoscope scope and displays a body cavity observation image of a subject imaged by the imaging module on a monitor screen, a flare is used to improve the quality of the captured image. Some measures have been taken.

  For example, in the electronic endoscope apparatus described in Patent Document 1 below, a flare stop is provided in front of a prism that changes the optical path of incident light to a substantially right angle on the light receiving surface side of the image sensor, and flare light reflected in the incident optical path is imaged. The light is not incident on the element.

  Further, in the electronic endoscope device described in Patent Document 2 below, a flare stop is provided on the peripheral edge of the cover glass that protects the light receiving surface of the image sensor so that flare light reflected in the incident optical path does not enter the image sensor. ing.

  The flare stop is formed of a light shielding mask or a light shielding film. A light shielding film generally used in an image sensor is for blocking light incident on a pixel (photodiode) of an optical black (OB) portion in order to detect a black level, and is provided inside the image sensor. It is done. On the other hand, a light-shielding film (light-shielding mask) for flare stop is provided in front of the image sensor outside the image sensor. The function of shading is the same, but one is intended to completely block the incident light on the black level detection pixel, and the other is intended to suppress the incidence of flare light of the incident light on the pixel. It is. For this reason, the position and area | region which provide a light shielding film differ.

  The flare stop is provided in front of the image sensor, but it is better to provide the flare stop as close as possible to the image sensor. Since the flare stop described in Patent Document 1 is provided in front of the prism disposed immediately before the image sensor, the flare light generated between the flare stop and the image sensor light-receiving surface is blocked from entering the image sensor. I can't.

  The flare stop described in Patent Document 2 is a back surface of a cover glass attached so as to cover the imaging element light receiving surface on an insulating resin covering connection terminals and wire bonding provided around the imaging element light receiving surface. Provided on the side (image sensor side). For this reason, the back surface of the cover glass provided with the flare stop and the imaging element light receiving surface are separated from each other, and flare light reflected by the inner peripheral surface of the resin layer enters the imaging element light receiving surface.

JP 2009-288682 A JP-A-9-205590

  An object of the present invention is to provide an imaging module for an endoscope that can satisfactorily remove flare, and an electronic endoscope apparatus in which the imaging module is housed in the distal end portion of an endoscope scope.

An imaging module for an endoscope of the present invention includes an objective lens optical system, a transparent optical member that takes in subject image light from the objective lens optical system and emits it from a flat light exit surface, a microlens non-mounted type, and a light An imaging element having a flat incident surface, an adhesive layer for closely bonding the light emitting surface of the transparent optical member and the light incident surface of the imaging element, and between the light emitting surface and the light incident surface A light-shielding mask for flare countermeasures, which is inserted into the objective lens optical system and the transparent optical member and is aligned with an image circle formed on the light incident surface of the image sensor and has an opening having a smaller diameter than the image circle. wherein the imaging device is an image pickup element for single-chip color image capturing three primary colors or complementary color filters are stacked in each pixel, the light shielding mask for the flare of the imaging element OB pixels for black level detection is provided in a region is shielded, but a configuration in which the light shielding mask for the flare as a light-shielding film of the OB pixels are also used.
The imaging module for an endoscope of the present invention is an objective lens optical system, a transparent optical member that takes in subject image light from the objective lens optical system and emits it from a flat light exit surface, and a microlens non-mounting type. And an imaging element having a flat light incident surface, an adhesive layer for closely bonding the light emitting surface of the transparent optical member and the light incident surface of the imaging element, the light emitting surface, and the light incident surface. A light shielding for flare countermeasures, which is interposed between the objective lens optical system and the transparent optical member and is aligned with an image circle formed on the light incident surface of the image sensor and has an opening having a smaller diameter than the image circle. A mask, and the image pickup device is a single-plate color image pickup device in which three primary color or complementary color filters are stacked on each pixel. The area to be shielded by the disk, in which a peripheral circuit of the image pickup element is formed.

  An electronic endoscope apparatus according to the present invention is characterized in that the above-described endoscope imaging module is built in a distal end portion of an endoscope.

  According to the present invention, since the light-shielding mask for preventing flare is provided immediately before the light incident surface of the image sensor, it is possible to satisfactorily block the incidence of flare light to the image sensor and to capture a high-quality image. Become.

1 is an overall configuration diagram of an electronic endoscope apparatus according to an embodiment of the present invention. It is a front end surface front view of the front-end | tip part of the electronic endoscope shown in FIG. It is a longitudinal cross-sectional view of the front-end | tip part of the electronic endoscope shown in FIG. FIG. 4 is an enlarged schematic cross-sectional view of the image sensor portion of FIG. 3. It is a disassembled perspective view of the prism of the embodiment shown in FIG. 3, a flare stop, and an image sensor. It is a figure which shows an example of the relationship between an image circle and an image pick-up element.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a configuration diagram showing the entire system of an electronic endoscope apparatus according to an embodiment of the present invention. An electronic endoscope apparatus (endoscope system) 10 according to the present embodiment includes an endoscope scope 12, a processor device 14 and a light source device 16 that constitute a main body device. The endoscope scope 12 includes a flexible insertion portion 20 that is inserted into a body cavity of a patient (subject), an operation portion 22 that is connected to a proximal end portion of the insertion portion 20, a processor device 14, and a light source. And a universal cord 24 connected to the device 16.

  A distal end portion 26 is connected to the distal end of the insertion portion 20, and an imaging chip (imaging device) 54 (see FIG. 3) for intra-body cavity imaging is built in the distal end portion 26. Behind the distal end portion 26 is provided a bending portion 28 in which a plurality of bending pieces are connected. When the angle knob 30 provided in the operation section 22 is operated, the bending section 28 is bent / moved in the vertical and horizontal directions by pushing / pulling the wire inserted in the insertion section 20. Thereby, the front-end | tip part 26 is orientated in the desired direction within a body cavity.

  A connector 36 is provided at the base end of the universal cord 24. The connector 36 is of a composite type and is connected to the light source device 16 in addition to being connected to the processor device 14.

  The processor device 14 supplies power to the endoscope scope 12 via a cable 68 (see FIG. 3) inserted into the universal cord 24, controls the driving of the imaging chip 54, and connects the cable 68 from the imaging chip 54. The received image signal is received, and various signal processing is performed on the received image signal to convert it into image data.

  The image data converted by the processor device 14 is displayed as an endoscopic image (observation image) on a monitor 38 connected to the processor device 14 by a cable. The processor device 14 is also electrically connected to the light source device 16 via the connector 36, and comprehensively controls the operation of the electronic endoscope device 10 including the light source device 16.

  FIG. 2 is a front view showing the distal end surface 26 a of the distal end portion 26 of the endoscope scope 12. As shown in FIG. 2, an observation window 40, an illumination window 42, a forceps outlet 44, and an air / water supply nozzle 46 are provided on the distal end surface 26 a of the distal end portion 26.

  The observation window 40 is arranged eccentric to the center and one side of the distal end surface 26a. Two illumination windows 42 are arranged at symmetrical positions with respect to the observation window 40, and irradiate illumination light from the light source device 16 to a site to be observed in the body cavity.

  The forceps outlet 44 is connected to a forceps channel 70 (see FIG. 3) disposed in the insertion portion 20 and communicates with a forceps port 34 (see FIG. 1) provided in the operation portion 22. Various treatment tools having an injection needle, a high-frequency knife or the like disposed at the distal end are inserted into the forceps port 34, and the distal ends of the various treatment instruments are ejected from the forceps outlet 44 into the body cavity.

  The air supply / water supply nozzle 46 is cleaned from the air supply / water supply device built in the light source device 16 in accordance with the operation of the air supply / water supply button 32 (see FIG. 1) provided in the operation unit 22. Water or air is jetted toward the observation window 40 or the body cavity.

  FIG. 3 is a longitudinal sectional view of the distal end portion 26 of the endoscope scope 12. As shown in FIG. 3, a lens barrel 52 that holds an objective lens optical system 50 for taking in image light of a site to be observed in the body cavity is disposed behind the observation window 40. The lens barrel 52 is attached so that the optical axis of the objective lens optical system 50 is parallel to the central axis of the insertion portion 20. Connected to the rear end of the lens barrel 52 is a prism 56 that guides the image light of the site to be observed via the objective lens optical system 50 toward the imaging chip 54 by bending it at a substantially right angle.

  The imaging chip 54 includes a single-chip imaging device 58 for color image imaging in which a signal reading circuit is formed on a semiconductor chip and a photoelectric conversion layer made of an organic layer is stacked thereon, and driving of the imaging device 58 and input of signals. A peripheral circuit 60 that performs output is an imaging chip formed on a semiconductor chip, and is mounted on a support substrate 62.

  The imaging surface (light receiving surface) 58 a of the imaging element 58 is disposed so as to face the light emitting surface of the prism 56. As will be described in detail later with reference to FIG. 4, the light receiving surface of the image sensor 58 is attached to the light emitting surface of the prism 56 with an adhesive via a flare stop.

  A plurality of input / output terminals 62 a are arranged in the width direction of the support substrate 62 at the rear end portion of the support substrate 62 extending toward the rear end of the insertion portion 20. A signal line 66 for mediating the exchange of various signals with the processor device 14 through the universal cord 24 is joined to the input / output terminal 62a. The input / output terminal 62a is electrically connected to the peripheral circuit 60 in the imaging chip 54 via wiring, bonding pads, etc. (not shown) formed on the support substrate 62.

  The signal lines 66 are collectively inserted into a flexible tubular cable 68. The cable 68 is inserted through each of the insertion unit 20, the operation unit 22, and the universal cord 24 and is connected to the connector 36.

  Although not shown in FIGS. 2 and 3, an illumination unit is provided in the back of the illumination window 42. The illumination unit is provided with a light guide end of a light guide that guides illumination light from the light source device 16, and the light exit end is provided facing the illumination window 42. Like the cable 68, the light guide is inserted through each of the insertion unit 20, the operation unit 22, and the universal cord 24, and the incident end is connected to the connector 36.

  FIG. 4 is an enlarged schematic cross-sectional view of the image sensor 58 portion shown in FIG. The photoelectric conversion layer stacked type imaging device 58 is formed on the semiconductor substrate 110. On the surface of the semiconductor substrate 110, a MOS circuit 71 such as a CMOS circuit as a signal readout circuit is formed for each pixel. The signal readout circuit may be a CCD type. JP-A-2011-243945, which was previously filed by the applicant of the present application and has already been disclosed, is known as a photoelectric conversion layer stacked type imaging device.

  An insulating layer 111 is laminated on the surface of the semiconductor substrate 110, and a wiring layer 112 is embedded in the insulating layer 111. The wiring layer 112 also functions as a shielding plate that prevents incident light that has leaked through the upper layer from entering the signal readout circuit 71 and the like.

  On the surface of the insulating layer 111, a plurality of pixel electrode films 113 are formed which are divided for each pixel and are arranged in a square lattice when viewed from above. Each pixel electrode film 113 is provided with a vertical wiring 114 extending up to the surface of the semiconductor substrate 110, and each vertical wiring 114 is connected to a signal charge storage unit (not shown) formed on the surface of the semiconductor substrate 110. .

  The signal readout circuit 71 provided for each pixel reads out a signal corresponding to the signal charge amount stored in the corresponding signal charge storage unit to the outside as a subject image signal. Note that the pixel electrode film 113 is provided in the effective pixel region and the OB portion in this embodiment.

  On the plurality of pixel electrode films 113 arranged in a square lattice pattern, a light receiving layer 103 having a photoelectric conversion function is laminated in a single configuration in common with each pixel electrode film. The upper electrode film (also referred to as a counter electrode film or a common electrode film) 104 is stacked on the pixel electrode film 113 as an upper layer on the light incident side. The light receiving surface 58a described in FIG. 3 corresponds to the light receiving layer 103, and a photoelectric conversion portion is formed by the light receiving layer 103, the lower electrode film (pixel electrode film) 113 and the upper electrode film 104 sandwiching the light receiving layer 103 vertically. .

  The upper electrode film 104 is electrically connected to the counter voltage supply electrode film 115 exposed on the surface of the insulating layer 111 through the wiring 116, and a required voltage is applied from the outside of the imaging device through the wiring 116. Is done.

  A protective layer 117 is laminated on the upper electrode film 104, and a color filter 120 corresponding to each pixel electrode film 113 is laminated thereon. For example, three primary color red (R), green (G), and blue (B) color filters are arranged in a Bayer array, or complementary color color filters are stacked. An overcoat layer (protective layer) 118 is laminated on the color filter layer 120.

  Since the upper electrode film 104 described above needs to make light incident on the light receiving layer 103, it is made of a conductive material transparent to the incident light. As a material of the upper electrode film 104, a transparent conductive oxide (TCO) having a high transmittance for visible light and a small resistance value can be used.

  A metal thin film such as Au (gold) can also be used. However, if the film thickness is reduced in order to obtain a transmittance of 90% or more, the resistance value increases drastically, so TCO is preferable. As TCO, indium tin oxide (ITO), indium oxide, tin oxide, fluorine-doped tin oxide (FTO), zinc oxide, aluminum-doped zinc oxide (AZO), titanium oxide, and the like can be preferably used. ITO is most preferable from the viewpoints of process simplicity, low resistance, and transparency. Note that the upper electrode film 104 is configured to be common to all pixels in the embodiment, but may be configured to be divided for each pixel and connected to a power source.

  The lower electrode film (pixel electrode film) 113 is a thin film divided for each pixel, and is made of a transparent or opaque conductive material. As a material of the lower electrode film 113, a metal such as Cr, In, Al, Ag, W, TiN (titanium nitride), or TCO can be used.

The protective layer 117 and the overcoat layer 118 are made of a transparent insulating material, silicon oxide film, silicon nitride film, zirconium oxide, tantalum oxide, titanium oxide, hafnium oxide, magnesium oxide, alumina (Al ₂ O ₃ ), polyparaxylene-based Resin, acrylic resin, all-fluorine transparent resin (Cytop), etc.

  The protective layer 117 and the overcoat layer 118 are formed by a known technique such as a chemical vapor deposition method (CVD method) or an atomic layer deposition method (ALD ALCVD), and are deposited by a CVD method, an atomic layer deposition method, or the like as necessary. It may be a multilayer film combined with a plurality of insulating films. The smoothing layer and the overcoat layer are formed and then smoothed and flattened by removing the convex portions by chemical mechanical polishing (CMP).

  The thickness of the protective layer 117 and the overcoat layer 118 fulfills their respective functions and is desirably as thin as possible, preferably 0.1 μm to 10 μm.

  As described with reference to FIG. 3, the peripheral circuit 60 is also formed on the semiconductor substrate 110. The image sensor 58 extends from the semiconductor substrate 110 to the overcoat layer 118, and the surface of the overcoat layer 118 of the image sensor 58 is directly attached to the light emitting surface 56 a of the prism 56 with the adhesive 120.

  At this time, for example, a flare diaphragm (light-shielding mask) 121 in which a hole 121a having a predetermined diameter is formed in a black and non-reflective thin film (for example, a thickness of 10 μm to 30 μm) such as a graphite film is used as an overcoat layer 118 and an adhesive layer 120. And put between. The adhesive layer 120 absorbs the thickness of the light shielding mask 121 and is fixed so that the light emitting surface 56a of the prism 56 and the surface of the overcoat layer 118 are parallel to each other.

  FIG. 5 is an exploded perspective view of the imaging chip 54, the light shielding mask (flare stop) 121, and the prism 56. The illustration of the objective lens optical system 50 to which the prism 56 is attached is omitted. The imaging module is manufactured by attaching the surface of the imaging element 58 of the imaging chip 54 to the light emitting surface of the prism 56 via the light shielding mask 121 via an adhesive.

  The opening 121a opened in the light shielding mask 121 is aligned to be concentric with the image circle formed on the light receiving surface of the image sensor 58 via the objective lens optical system 50 and the prism 56, and is slightly smaller in diameter than the image circle. It is opened so as to be a circle.

  The image sensor 58 of this embodiment is a top lens (microlens) non-mounting type. This is because even if a top lens is not provided, the entire light receiving surface can be used as a light receiving element (photoelectric conversion unit) and the light receiving sensitivity is high.

  For this reason, the surface of the image sensor 58 (the surface of the overcoat layer 118) is flat. This surface is attached in close contact with the light emitting surface (flat surface) of the prism 56 with an adhesive 120 with a light shielding mask (flare stop) 121 interposed therebetween. The area to be in close contact is the entire area where the light emitting surface of the prism 56 and the surface of the image sensor 58 overlap.

  As a result, the prism 56 and the image sensor 58 are fixed without any gap therebetween, and the surface of the image sensor 58 is protected by the prism 56 and is also moisture-proof.

  If each pixel of the image sensor has a top lens, if the adhesive 120 is applied so as to fill the gap between the top lenses, the difference in refractive index between the top lens and the gap becomes small. Function will be reduced. For this reason, in the case of a top lens mounting type image pickup device, it is necessary to attach a cover glass slightly apart from the top lens, for example, as described in JP 2010-98066 A, so as not to impair the lens function.

  That is, it is necessary to provide the flare stop 121 in the gap between the top lens and the cover glass. In this way, stray light generated by irregular reflection of incident light after passing through the flare stop 121 may enter each pixel and a flare image may be captured. Further, since there is a gap, it is necessary to prevent moisture.

  However, in the above-described embodiment of the present invention, since the gap is not present, flare can be minimized, and further, it is not necessary to separately provide moisture-proofing on the light receiving surface of the image sensor.

  In the above-described embodiment, the flare stop 121 is formed of a black film. However, a black paint is thickly applied to the surface of the overcoat layer 118 by a printing technique to form the flare stop 121, and the overcoat layer 118 of the image sensor 58 is directly attached to the light emitting surface of the prism 56 with the adhesive 120. May be attached.

  Or, conversely, a black paint is thickly applied to the light exit surface of the prism 56 by a printing technique to form the flare stop 121, and the overcoat layer 118 of the image sensor 58 is directly applied to the light exit surface of the prism 56 with the adhesive 120. It may be pasted.

  As the adhesive 120, for example, a thermosetting transparent resin or an ultraviolet curable transparent resin may be used, and heat or ultraviolet light is applied to the adhesive surface while the prism 56 and the image sensor 58 are kept in close contact with each other. Thus, the adhesive 120 can be cured.

  FIG. 6 is a diagram of the image sensor 58 side as viewed from the light exit surface of the prism 56, and is a diagram illustrating the relationship between the image circle (≈the light shielding mask opening 121a) and the image sensor 58. On the light-receiving surface of the rectangular imaging element 58, an image circle of incident light that is bent in a right angle direction by the prism 56 through the objective lens optical system is formed, and a light-shielding mask having an opening 121a that matches the image circle. A (flare stop) 121 is provided.

  In the example shown in the figure, regions shielded by the flare stop 121 are formed at the four corners (cross-hatched regions) 72 of the rectangular light receiving surface of the image sensor 58. In the present embodiment, the pixel electrode film 113, the light receiving layer 103, the upper electrode film 104, and the color filter layer 120 described above are also provided in this region 72.

  That is, the OB portion is provided in the region 72 shielded by the flare stop 121, and the flare stop 121 is also used as the light shielding film of the OB portion. Accordingly, it is not necessary to provide an OB portion separately from the area of the image sensor 58, and the image sensor 58 can be reduced in size (for example, the photoelectric conversion film stacked imaging described in Japanese Patent Application Laid-Open No. 2011-243945 described above). The element is provided with an image sensor and an OB portion in separate areas.)

  In addition, instead of providing the OB portion in the region 72, the size may be reduced by providing another circuit (for example, a peripheral circuit).

  By providing an OB portion in the region 72 and mounting a color filter on the OB pixel, it is possible to obtain an OB signal for an R filter mounted pixel, an OB signal for a G filter mounted pixel, and an OB signal for a B filter mounted pixel. . The offset amount of the black level signal is often different for each color of the mounted color filter. For this reason, the OB pixel integrated value for each color of the color filter can be obtained, the offset amount can be calculated with high accuracy, and a high-quality image with less noise can be taken.

  The detection signal of the OB pixel is not read except when necessary, and it is possible to speed up the signal reading and save power.

  As in the above-described embodiment, the light incident surface of the image sensor 58 can be brought into close contact with the light emitting surface 56 a of the prism 56 over the entire overlapping region. The photoelectric conversion layer (light receiving layer) 103 is formed on the semiconductor substrate 110. This is because of a laminated structure. That is, it is because the photoelectric conversion layer laminated portion protrudes upward from the surface of the semiconductor substrate (a structure in which wire bonding does not interfere). The connection pads connected to the circuit elements formed on the semiconductor are formed on the surface of the semiconductor substrate, and the light incident surface of the image sensor is formed at a position away from the semiconductor substrate. It can stick and affix to the light-projection surface.

  For this reason, the above-described embodiment can also be applied to a backside illumination type image pickup device in which the signal readout circuit and its connection terminal and the incident light incident surface are opposite to each other. The back-illuminated image sensor does not need to be provided with a top lens, and the light incident surface is flat. For this reason, it can be fixed in close contact with the light incident surface of the image sensor on a wide area of the light exit surface of the prism.

  In the above-described embodiment, the light incident optical axis is bent in a right angle direction using the prism 56. However, as described in Patent Document 2, for example, an imaging element that directly receives image light emitted from an objective lens optical system directly on a light receiving surface without using a prism, without using a prism, Glass may be used instead of a prism. In this case as well, a flare stop 121 may be inserted between the cover glass and the light receiving surface of the image sensor, and the two may be bonded together.

  As described above, the imaging module for an endoscope according to the embodiment includes an objective lens optical system, a transparent optical member that captures subject image light from the objective lens optical system and emits it from a flat light exit surface, and a microlens. An imaging device that is not mounted and has a flat light incident surface, an adhesive layer that tightly bonds the light emitting surface of the transparent optical member and the light incident surface of the imaging device, the light emitting surface, and the light emitting surface A flare that is interposed between a light incident surface, passes through the objective lens optical system and the transparent optical member, is aligned with an image circle formed on the light incident surface of the image sensor, and an opening having a smaller diameter than the image circle is formed. And a light shielding mask for countermeasures.

  In the endoscope imaging module of the embodiment, the imaging element is a photoelectric conversion layer stacked type.

  In the endoscope imaging module according to the embodiment, the transparent optical member bends the optical path of the subject image light emitted from the objective lens optical system in a substantially right angle direction so as to enter the light incident surface of the imaging element. It is a right angle prism.

  In the endoscope imaging module according to the embodiment, the transparent optical member is a cover formed of a parallel plate that transmits the subject image light emitted from the objective lens optical system and enters the light incident surface of the imaging element. It is characterized by being glass.

  In addition, the image pickup device of the endoscope image pickup module of the embodiment is a single-plate color image pickup image pickup device in which three primary color or complementary color system color filters are stacked on each pixel.

  In the endoscope imaging module according to the embodiment, an OB pixel for black level detection is provided in a region shielded by the shading mask for preventing flare in the imaging element, and the light shielding film of the OB pixel serves as the light shielding film. The light-shielding mask for preventing flare is also used as a feature.

  In addition, the OB pixel of the endoscope imaging module according to the embodiment is characterized in that a color filter for detecting a black level signal for each color of the color filter is stacked.

  The endoscope imaging module according to the embodiment is characterized in that a peripheral circuit of the imaging element is formed in an area of the imaging element that is shielded by the light shielding mask for preventing flare.

  Moreover, the electronic endoscope apparatus according to the embodiment is characterized in that the endoscope imaging module described in any one of the above is built in the distal end portion of the endoscope scope.

  According to the embodiment described above, since the anti-flare mask is provided immediately before the light incident surface of the image sensor, it is possible to prevent the flare light from being incident on the image sensor light receiving surface, and a high-quality image can be obtained. An image can be taken.

  The imaging module for an endoscope according to the present invention can effectively prevent flare light from entering the light-receiving surface of the imaging device, and thus is useful when incorporated in the distal end of a scope of an electronic endoscope apparatus.

10 Electronic Endoscope Device (Endoscope System)
DESCRIPTION OF SYMBOLS 12 Endoscope scope 14 Processor apparatus 16 Light source apparatus 26 Tip part 38 Monitor 40 Observation window 42 Illumination window 50 Objective lens optical system 54 Imaging chip 56 Right angle prism 56a Prism light emission surface 58 Imaging element (image sensor)
58a Image sensor light receiving surface 62 Substrate 68 Cable 71 Signal readout circuit 103 Light receiving layer (photoelectric conversion layer)
104 Upper electrode film 110 Semiconductor substrate 113 Pixel electrode film 118 Overcoat layer 120 Color filter layer 121 Shading mask (flare stop)
121a Flare aperture

Claims (10)

An objective lens optical system, a transparent optical member that captures subject image light from the objective lens optical system and emits it from a planar light exit surface, a microlens non-mounted image sensor with a flat light incident surface, and the transparent An adhesive layer for closely bonding the light emitting surface of the optical member and the light incident surface of the imaging element; and the objective lens optical system and the optical system interposed between the light emitting surface and the light incident surface A light-shielding mask for anti-flare that is aligned with an image circle formed on a light incident surface of the image sensor through a transparent optical member and has an opening having a smaller diameter than the image circle;
The image sensor is an image sensor for imaging a single plate color image in which color filters of three primary colors or complementary colors are stacked on each pixel,
A black level detection OB pixel is provided in a region shielded by the flare countermeasure light shielding mask of the image sensor, and the flare countermeasure light shielding mask is also used as a light shielding film of the OB pixel. An imaging module for an endoscope.   The endoscope imaging module according to claim 1, wherein the imaging element is a photoelectric conversion layer stacked type.   3. The endoscope imaging module according to claim 1, wherein the transparent optical member bends an optical path of subject image light emitted from the objective lens optical system in a substantially perpendicular direction. An imaging module for an endoscope which is a right-angle prism that is incident on the light incident surface of the endoscope.   3. The endoscope imaging module according to claim 1, wherein the transparent optical member transmits object image light emitted from the objective lens optical system to a light incident surface of the imaging element. An imaging module for an endoscope, which is a cover glass made of parallel flat plates to be incident. The endoscope imaging module according to any one of claims 1 to 4 , wherein a color filter for detecting a black level signal for each color of the color filter is stacked on the OB pixel. An imaging module for an endoscope. An objective lens optical system, a transparent optical member that captures subject image light from the objective lens optical system and emits it from a planar light exit surface, a microlens non-mounted image sensor with a flat light incident surface, and the transparent An adhesive layer for closely bonding the light emitting surface of the optical member and the light incident surface of the imaging element; and the objective lens optical system and the optical system interposed between the light emitting surface and the light incident surface A light-shielding mask for anti-flare that is aligned with an image circle formed on a light incident surface of the image sensor through a transparent optical member and has an opening having a smaller diameter than the image circle;
The image sensor is an image sensor for imaging a single plate color image in which color filters of three primary colors or complementary colors are stacked on each pixel,
An imaging module for an endoscope, wherein a peripheral circuit of the imaging element is formed in an area shielded by the light shielding mask for preventing flare in the imaging element.   The endoscope imaging module according to claim 6, wherein the imaging element is a photoelectric conversion layer stacked type.   The endoscope imaging module according to claim 6 or 7, wherein the transparent optical member bends an optical path of subject image light emitted from the objective lens optical system in a substantially right angle direction. An imaging module for an endoscope which is a right-angle prism that is incident on the light incident surface of the endoscope.   8. The endoscope imaging module according to claim 6, wherein the transparent optical member transmits object image light emitted from the objective lens optical system to a light incident surface of the imaging element. 9. An imaging module for an endoscope, which is a cover glass made of parallel flat plates to be incident. An electronic endoscope apparatus in which the endoscope imaging module according to any one of claims 1 to 9 is built in a distal end portion of an endoscope scope.

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